This invention relates to electrical resistance welders, and more particularly to an electrical resistance welder which is suitable for welding relatively small materials.
In welding small materials such as thin metal wires, it is necessary to apply a relatively small current for a short time. In such a case, heretofore a capacitor type welder is employed. However, the welder is disadvantageous in that it takes a relatively long time to charge the capacitor of the welder, and it is impossible to increase the welding rate because of the service life of the capacitor.
In order to overcome this difficulty, a welding method has been proposed in which the half cycles of a commercial main frequency are utilized for welding. However, it is difficult to correctly supply current to the materials which are repeatedly fed for welding at high speed independently of the phase of the AC power source.